From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net v1 1/1] net: fec: Fix Transmitted bytes counter
Date: Mon, 01 Jul 2013 13:40:00 -0700 (PDT)
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From: Duan Fugang-B38611 <B38611@freescale.com>
Date: Fri, 28 Jun 2013 02:11:30 +0000

> On 06/28/13 02:25, Jim Baxter wrote:
> 
>> diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
>> index ed6180e..05a5f76 100644
>> --- a/drivers/net/ethernet/freescale/fec_main.c
>> +++ b/drivers/net/ethernet/freescale/fec_main.c
>> @@ -738,6 +738,7 @@ fec_enet_tx(struct net_device *ndev)
>>  				ndev->stats.tx_carrier_errors++;
>>  		} else {
>>  			ndev->stats.tx_packets++;
>> +			ndev->stats.tx_bytes += bdp->cbd_datlen;
>>  		}
>>  
>>  		if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS) &&
>> --
> You cannot stat. tx_bytes in here, since stat.tx_bytes indicate that all bytes sent by MAC regardless whether there have error packets or not.
> You must add the stat. at xmit function as below:

I completely disagree.

tx_bytes indicates what actually made it to the wires, so Jim's original
patch is the correct one.

Every single driver I have ever written, always increments tx_bytes in
the transmit completion handler, not when the device layer gives the
packet to the driver.